The acpi_table_parse() function has a callback that passes a pointer to a table_header. Add a new function which takes this pointer and parses its entries. This eliminates the need to re-traverse all the tables for each call. e.g. as in acpi_table_parse_madt() which is normally called after acpi_table_parse().
Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org --- drivers/acpi/tables.c | 69 +++++++++++++++++++++++++++++++++++---------------- include/linux/acpi.h | 4 +++ 2 files changed, 51 insertions(+), 22 deletions(-)
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index 5837f85..b7bd6a3 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -199,19 +199,15 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header) } }
- int __init -acpi_table_parse_entries(char *id, - unsigned long table_size, - int entry_id, - acpi_tbl_entry_handler handler, - unsigned int max_entries) +acpi_parse_entries(unsigned long table_size, + acpi_tbl_entry_handler handler, + struct acpi_table_header *table_header, + int entry_id, unsigned int max_entries) { - struct acpi_table_header *table_header = NULL; struct acpi_subtable_header *entry; unsigned int count = 0; unsigned long table_end; - acpi_size tbl_size;
if (acpi_disabled) return -ENODEV; @@ -219,16 +215,14 @@ acpi_table_parse_entries(char *id, if (!handler) return -EINVAL;
- if (strncmp(id, ACPI_SIG_MADT, 4) == 0) - acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size); - else - acpi_get_table_with_size(id, 0, &table_header, &tbl_size); - if (!table_header) { - printk(KERN_WARNING PREFIX "%4.4s not present\n", id); + pr_warn(PREFIX "Table header not present\n"); return -ENODEV; }
+ if (!table_size) + table_size = table_header->length; + table_end = (unsigned long)table_header + table_header->length;
/* Parse all entries looking for a match. */ @@ -240,15 +234,18 @@ acpi_table_parse_entries(char *id, table_end) { if (entry->type == entry_id && (!max_entries || count++ < max_entries)) - if (handler(entry, table_end)) + if (handler(entry, table_end)) { + count = -EINVAL; goto err; + }
/* * If entry->length is 0, break from this loop to avoid * infinite loop. */ if (entry->length == 0) { - pr_err(PREFIX "[%4.4s:0x%02x] Invalid zero length\n", id, entry_id); + pr_err(PREFIX "[0x%02x] Invalid zero length\n", entry_id); + count = -EINVAL; goto err; }
@@ -256,15 +253,43 @@ acpi_table_parse_entries(char *id, ((unsigned long)entry + entry->length); } if (max_entries && count > max_entries) { - printk(KERN_WARNING PREFIX "[%4.4s:0x%02x] ignored %i entries of " - "%i found\n", id, entry_id, count - max_entries, count); + printk(KERN_WARNING PREFIX "[0x%02x] ignored %i entries of " + "%i found\n", entry_id, count - max_entries, count); }
- early_acpi_os_unmap_memory((char *)table_header, tbl_size); - return count; err: - early_acpi_os_unmap_memory((char *)table_header, tbl_size); - return -EINVAL; + early_acpi_os_unmap_memory((char *)table_header, (acpi_size)table_size); + return count; +} + +int __init +acpi_table_parse_entries(char *id, + unsigned long table_size, + int entry_id, + acpi_tbl_entry_handler handler, + unsigned int max_entries) +{ + struct acpi_table_header *table_header = NULL; + acpi_size tbl_size; + + if (acpi_disabled) + return -ENODEV; + + if (!handler) + return -EINVAL; + + if (strncmp(id, ACPI_SIG_MADT, 4) == 0) + acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size); + else + acpi_get_table_with_size(id, 0, &table_header, &tbl_size); + + if (!table_header) { + pr_warn("%4.4s not present\n", id); + return -ENODEV; + } + + return acpi_parse_entries(table_header->length, handler, table_header, + entry_id, max_entries); }
int __init diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 1151a1d..da959fd 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -118,6 +118,10 @@ int acpi_numa_init (void);
int acpi_table_init (void); int acpi_table_parse(char *id, acpi_tbl_table_handler handler); +int __init acpi_parse_entries(unsigned long table_size, + acpi_tbl_entry_handler handler, + struct acpi_table_header *table_header, + int entry_id, unsigned int max_entries); int __init acpi_table_parse_entries(char *id, unsigned long table_size, int entry_id, acpi_tbl_entry_handler handler,
Hi Ashwin,
On 2014-3-20 7:09, Ashwin Chaugule wrote:
The acpi_table_parse() function has a callback that passes a pointer to a table_header. Add a new function which takes this pointer and parses its entries. This eliminates the need to re-traverse all the tables for each call. e.g. as in acpi_table_parse_madt() which is normally called after acpi_table_parse().
Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org
drivers/acpi/tables.c | 69 +++++++++++++++++++++++++++++++++++---------------- include/linux/acpi.h | 4 +++ 2 files changed, 51 insertions(+), 22 deletions(-)
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index 5837f85..b7bd6a3 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -199,19 +199,15 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header) } }
int __init -acpi_table_parse_entries(char *id,
unsigned long table_size,int entry_id,acpi_tbl_entry_handler handler,unsigned int max_entries)+acpi_parse_entries(unsigned long table_size,
acpi_tbl_entry_handler handler,struct acpi_table_header *table_header,int entry_id, unsigned int max_entries){
- struct acpi_table_header *table_header = NULL; struct acpi_subtable_header *entry; unsigned int count = 0; unsigned long table_end;
- acpi_size tbl_size;
if (acpi_disabled) return -ENODEV; @@ -219,16 +215,14 @@ acpi_table_parse_entries(char *id, if (!handler) return -EINVAL;
- if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);- else
acpi_get_table_with_size(id, 0, &table_header, &tbl_size);- if (!table_header) {
printk(KERN_WARNING PREFIX "%4.4s not present\n", id);
pr_warn(PREFIX "Table header not present\n");
Can you rebase this patch on the branch of linux-next of linux-pm tree? PREFIX was removed by me and I used pr_fmt() instead.
Thanks Hanjun
On 20 March 2014 04:25, Hanjun Guo hanjun.guo@linaro.org wrote:
Can you rebase this patch on the branch of linux-next of linux-pm tree? PREFIX was removed by me and I used pr_fmt() instead.
Will do.
On 20.03.2014 00:09, Ashwin Chaugule wrote:
The acpi_table_parse() function has a callback that passes a pointer to a table_header. Add a new function which takes this pointer and parses its entries. This eliminates the need to re-traverse all the tables for each call. e.g. as in acpi_table_parse_madt() which is normally called after acpi_table_parse().
Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org
drivers/acpi/tables.c | 69 +++++++++++++++++++++++++++++++++++---------------- include/linux/acpi.h | 4 +++ 2 files changed, 51 insertions(+), 22 deletions(-)
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index 5837f85..b7bd6a3 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -199,19 +199,15 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header) } }
- int __init
-acpi_table_parse_entries(char *id,
unsigned long table_size,int entry_id,acpi_tbl_entry_handler handler,unsigned int max_entries)+acpi_parse_entries(unsigned long table_size,
acpi_tbl_entry_handler handler,struct acpi_table_header *table_header,int entry_id, unsigned int max_entries)
struct acpi_table_header *table_header = NULL; struct acpi_subtable_header *entry; unsigned int count = 0; unsigned long table_end;
acpi_size tbl_size;
if (acpi_disabled) return -ENODEV;
@@ -219,16 +215,14 @@ acpi_table_parse_entries(char *id, if (!handler) return -EINVAL;
- if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);- else
acpi_get_table_with_size(id, 0, &table_header, &tbl_size);- if (!table_header) {
printk(KERN_WARNING PREFIX "%4.4s not present\n", id);
pr_warn(PREFIX "Table header not present\n");return -ENODEV; }
if (!table_size)
table_size = table_header->length;
If table_size == 0, that would causes 'entry' and 'table_end' are equal and no entries at all. For that case I would suggest to print error and return.
Tomasz
table_end = (unsigned long)table_header + table_header->length;
/* Parse all entries looking for a match. */ @@ -240,15 +234,18 @@ acpi_table_parse_entries(char *id, table_end) { if (entry->type == entry_id && (!max_entries || count++ < max_entries))
if (handler(entry, table_end))
if (handler(entry, table_end)) {count = -EINVAL; goto err;}/*
- If entry->length is 0, break from this loop to avoid
- infinite loop.
*/ if (entry->length == 0) {
pr_err(PREFIX "[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
pr_err(PREFIX "[0x%02x] Invalid zero length\n", entry_id);count = -EINVAL; goto err;@@ -256,15 +253,43 @@ acpi_table_parse_entries(char *id, ((unsigned long)entry + entry->length); } if (max_entries && count > max_entries) {
printk(KERN_WARNING PREFIX "[%4.4s:0x%02x] ignored %i entries of ""%i found\n", id, entry_id, count - max_entries, count);
printk(KERN_WARNING PREFIX "[0x%02x] ignored %i entries of ""%i found\n", entry_id, count - max_entries, count);
- early_acpi_os_unmap_memory((char *)table_header, tbl_size);
- return count; err:
- early_acpi_os_unmap_memory((char *)table_header, tbl_size);
- return -EINVAL;
- early_acpi_os_unmap_memory((char *)table_header, (acpi_size)table_size);
- return count;
Changelog is saying that acpi_parse_entries() takes already mapped table and parses entries. IMO, caller should takes care about unmapping table. It can be still parsed using different ID later on.
Tomasz
+}
+int __init +acpi_table_parse_entries(char *id,
unsigned long table_size,int entry_id,acpi_tbl_entry_handler handler,unsigned int max_entries)+{
struct acpi_table_header *table_header = NULL;
acpi_size tbl_size;
if (acpi_disabled)
return -ENODEV;if (!handler)
return -EINVAL;if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);else
acpi_get_table_with_size(id, 0, &table_header, &tbl_size);if (!table_header) {
pr_warn("%4.4s not present\n", id);return -ENODEV;}
return acpi_parse_entries(table_header->length, handler, table_header,
entry_id, max_entries);}
int __init
diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 1151a1d..da959fd 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -118,6 +118,10 @@ int acpi_numa_init (void);
int acpi_table_init (void); int acpi_table_parse(char *id, acpi_tbl_table_handler handler); +int __init acpi_parse_entries(unsigned long table_size,
acpi_tbl_entry_handler handler,struct acpi_table_header *table_header,int entry_id, unsigned int max_entries);
On 20.03.2014 11:05, Tomasz Nowicki wrote:
On 20.03.2014 00:09, Ashwin Chaugule wrote:
The acpi_table_parse() function has a callback that passes a pointer to a table_header. Add a new function which takes this pointer and parses its entries. This eliminates the need to re-traverse all the tables for each call. e.g. as in acpi_table_parse_madt() which is normally called after acpi_table_parse().
Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org
drivers/acpi/tables.c | 69 +++++++++++++++++++++++++++++++++++---------------- include/linux/acpi.h | 4 +++ 2 files changed, 51 insertions(+), 22 deletions(-)
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index 5837f85..b7bd6a3 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -199,19 +199,15 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header) } }
- int __init
-acpi_table_parse_entries(char *id,
unsigned long table_size,int entry_id,acpi_tbl_entry_handler handler,unsigned int max_entries)+acpi_parse_entries(unsigned long table_size,
acpi_tbl_entry_handler handler,struct acpi_table_header *table_header,int entry_id, unsigned int max_entries)
struct acpi_table_header *table_header = NULL; struct acpi_subtable_header *entry; unsigned int count = 0; unsigned long table_end;
acpi_size tbl_size;
if (acpi_disabled) return -ENODEV;
@@ -219,16 +215,14 @@ acpi_table_parse_entries(char *id, if (!handler) return -EINVAL;
- if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
acpi_get_table_with_size(id, acpi_apic_instance,&table_header, &tbl_size);
- else
acpi_get_table_with_size(id, 0, &table_header, &tbl_size);if (!table_header) {printk(KERN_WARNING PREFIX "%4.4s not present\n", id);
pr_warn(PREFIX "Table header not present\n"); return -ENODEV; }if (!table_size)
table_size = table_header->length;If table_size == 0, that would causes 'entry' and 'table_end' are equal and no entries at all. For that case I would suggest to print error and return.
Tomasz
table_end = (unsigned long)table_header + table_header->length; /* Parse all entries looking for a match. */@@ -240,15 +234,18 @@ acpi_table_parse_entries(char *id, table_end) { if (entry->type == entry_id && (!max_entries || count++ < max_entries))
if (handler(entry, table_end))
if (handler(entry, table_end)) {count = -EINVAL; goto err;} /* * If entry->length is 0, break from this loop to avoid * infinite loop. */ if (entry->length == 0) {
pr_err(PREFIX "[%4.4s:0x%02x] Invalid zero length\n", id,entry_id);
pr_err(PREFIX "[0x%02x] Invalid zero length\n", entry_id);count = -EINVAL; goto err; }@@ -256,15 +253,43 @@ acpi_table_parse_entries(char *id, ((unsigned long)entry + entry->length); } if (max_entries && count > max_entries) {
printk(KERN_WARNING PREFIX "[%4.4s:0x%02x] ignored %i entriesof "
"%i found\n", id, entry_id, count - max_entries, count);
printk(KERN_WARNING PREFIX "[0x%02x] ignored %i entries of ""%i found\n", entry_id, count - max_entries, count); }
- early_acpi_os_unmap_memory((char *)table_header, tbl_size);
- return count; err:
- early_acpi_os_unmap_memory((char *)table_header, tbl_size);
- return -EINVAL;
- early_acpi_os_unmap_memory((char *)table_header,
(acpi_size)table_size);
- return count;
Changelog is saying that acpi_parse_entries() takes already mapped table and parses entries. IMO, caller should takes care about unmapping table. It can be still parsed using different ID later on.
Tomasz
+}
+int __init +acpi_table_parse_entries(char *id,
unsigned long table_size,int entry_id,acpi_tbl_entry_handler handler,unsigned int max_entries)+{
- struct acpi_table_header *table_header = NULL;
- acpi_size tbl_size;
- if (acpi_disabled)
return -ENODEV;- if (!handler)
return -EINVAL;- if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
acpi_get_table_with_size(id, acpi_apic_instance,&table_header, &tbl_size);
- else
acpi_get_table_with_size(id, 0, &table_header, &tbl_size);- if (!table_header) {
pr_warn("%4.4s not present\n", id);return -ENODEV;- }
- return acpi_parse_entries(table_header->length, handler,
table_header,
entry_id, max_entries);
Also, first argument of acpi_parse_entries() expect subtable start point offset, but now it points to the end of table.
Tomasz
}
int __init diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 1151a1d..da959fd 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -118,6 +118,10 @@ int acpi_numa_init (void);
int acpi_table_init (void); int acpi_table_parse(char *id, acpi_tbl_table_handler handler); +int __init acpi_parse_entries(unsigned long table_size,
acpi_tbl_entry_handler handler,struct acpi_table_header *table_header,int entry_id, unsigned int max_entries);
On 20 March 2014 06:16, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
- return acpi_parse_entries(table_header->length, handler,
table_header,
entry_id, max_entries);Also, first argument of acpi_parse_entries() expect subtable start point offset, but now it points to the end of table.
Not sure what you mean. First arg of acpi_parse_entries expects table_size, not an offset.
Ashwin
On 20.03.2014 14:27, Ashwin Chaugule wrote:
On 20 March 2014 06:16, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
- return acpi_parse_entries(table_header->length, handler,
table_header,
entry_id, max_entries);Also, first argument of acpi_parse_entries() expect subtable start point offset, but now it points to the end of table.
Not sure what you mean. First arg of acpi_parse_entries expects table_size, not an offset.
As I mentioned in previous mail, first args of acpi_parse_entries will lead us to first MADT entry list. By passing table_header->length we will get at the end of MADT entry list. IMO, we should use table_size (snd argument of acpi_table_parse_entries()) instead of table_header->length.
Tomasz
On 20 March 2014 10:06, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
On 20.03.2014 14:27, Ashwin Chaugule wrote:
On 20 March 2014 06:16, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
- return acpi_parse_entries(table_header->length, handler,
table_header,
entry_id, max_entries);Also, first argument of acpi_parse_entries() expect subtable start point offset, but now it points to the end of table.
Not sure what you mean. First arg of acpi_parse_entries expects table_size, not an offset.
As I mentioned in previous mail, first args of acpi_parse_entries will lead us to first MADT entry list. By passing table_header->length we will get at the end of MADT entry list. IMO, we should use table_size (snd argument of acpi_table_parse_entries()) instead of table_header->length.
Right. I get the difference between tbl_size and table_header->length. But we need to rethink this apci_parse_entries() function and its use case again. If the caller is expected to pass tbl_size, then we're back full circle to using acpi_get_table_with_size() in the caller, which is kinda self defeating. :)
Ashwin
On 20.03.2014 15:39, Ashwin Chaugule wrote:
On 20 March 2014 10:06, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
On 20.03.2014 14:27, Ashwin Chaugule wrote:
On 20 March 2014 06:16, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
- return acpi_parse_entries(table_header->length, handler,
table_header,
entry_id, max_entries);Also, first argument of acpi_parse_entries() expect subtable start point offset, but now it points to the end of table.
Not sure what you mean. First arg of acpi_parse_entries expects table_size, not an offset.
As I mentioned in previous mail, first args of acpi_parse_entries will lead us to first MADT entry list. By passing table_header->length we will get at the end of MADT entry list. IMO, we should use table_size (snd argument of acpi_table_parse_entries()) instead of table_header->length.
Right. I get the difference between tbl_size and table_header->length. But we need to rethink this apci_parse_entries() function and its use case again. If the caller is expected to pass tbl_size, then we're back full circle to using acpi_get_table_with_size() in the caller, which is kinda self defeating. :)
I believe that the most useful case for apci_parse_entries() is when you already get table pointer and want to do many things on entries. Then you don't have to traverse all ACPI tables list and do map/unmap dance over and over again :) and that's what your changelog is saying too :)
Tomasz
Hi Tomasz,
On 20 March 2014 06:05, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
if (!table_size)table_size = table_header->length;If table_size == 0, that would causes 'entry' and 'table_end' are equal and no entries at all. For that case I would suggest to print error and return.
Hm. tbl_size and table_header->length are not the same. This needs to be revisited.
Changelog is saying that acpi_parse_entries() takes already mapped table and parses entries. IMO, caller should takes care about unmapping table. It can be still parsed using different ID later on.
Although I generally agree that mapping/umapping should be done in the caller, it seems umapping in this manner is baked in APCI core code and I didn't want to change too many things at once without causing unintentional side effects elsewhere.
Thanks, Ashwin
On 20.03.2014 14:25, Ashwin Chaugule wrote:
Hi Tomasz,
On 20 March 2014 06:05, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
if (!table_size)table_size = table_header->length;If table_size == 0, that would causes 'entry' and 'table_end' are equal and no entries at all. For that case I would suggest to print error and return.
Hm. tbl_size and table_header->length are not the same. This needs to be revisited.
Indeed, table_size is used to find out where entry list starts. table_header->length in turn, is used to find out end of entry list. If we pass table_size = 0, then we will parse none of entries.
Changelog is saying that acpi_parse_entries() takes already mapped table and parses entries. IMO, caller should takes care about unmapping table. It can be still parsed using different ID later on.
Although I generally agree that mapping/umapping should be done in the caller, it seems umapping in this manner is baked in APCI core code and I didn't want to change too many things at once without causing unintentional side effects elsewhere.
You will not cause any side effects if unmapping will stay in acpi_table_parse_entries().
Tomasz
On 20 March 2014 09:48, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
Although I generally agree that mapping/umapping should be done in the caller, it seems umapping in this manner is baked in APCI core code and I didn't want to change too many things at once without causing unintentional side effects elsewhere.
You will not cause any side effects if unmapping will stay in acpi_table_parse_entries().
What if callers only call acpi_parse_entries()?
Ashwin
On 20.03.2014 14:53, Ashwin Chaugule wrote:
On 20 March 2014 09:48, Tomasz Nowicki tomasz.nowicki@linaro.org wrote:
Although I generally agree that mapping/umapping should be done in the caller, it seems umapping in this manner is baked in APCI core code and I didn't want to change too many things at once without causing unintentional side effects elsewhere.
You will not cause any side effects if unmapping will stay in acpi_table_parse_entries().
What if callers only call acpi_parse_entries()?
acpi_parse_entries() requires already mapped MADT table and as you agreed on caller mapping/unmapping responsibility, caller need to unmap MADT table after all. I mean sth like that:
1. Get MADT table pointer 2. Map MADT table 3. Use acpi_parse_entries() as many times as you wish (some calls can return error but you don't have to map MADT again) 4. Unmap MADT table
What do you think?
Tomasz
-
Ashwin Chaugule -
Hanjun Guo -
Tomasz Nowicki